Magneto starter



.I. F. ADYE.

MAQNETO STARTER. APPLlCATlON FILED DEC. 17. 1920.

Patented Nov. 21, 1922.

Patented Nov. 21, 1922.

JOHN FIFIELD ADYE, OF CHESHIRE, ENGLAND.

MAGNETO STARTER.

Application filed December 17, 1920. Serial No. 431,468.

'1 '0 all re/r0722 it may concern:

Be it known that 1, JOHN FIFIELL) AoYn, a SllbjGCt of the King of England, residing at Cheshire, England, have invented certain new and useful Improvements in Magneto Starters, of which the following is a specification. p

This invention is for. improvements in or relating to magneto-starters of the type wherein a driving-member is connected to the driven-member, which maybe the magneto-armature shaft, through the medium of a spring, and a pawl is provided to hold back the driven-member whilst the spring is loaded by turning the driving-member, which pawl is afterwards automatically tripped so that the driven-member suddenly advances under the actioniof the spring, and thus a quick turn is given to the mag neto-armature and the requisite spark is produced. i

Some of the objects of the present invention are to provide a starter which may be less expensive to manufacture than those at present in use, to provide a simple means for throwing the pawl out when a certain speed of rotation has been attained, such means involving little if any additional expense to the manufacture, and to provide a form of mechanism wherein the same partscan be assembled for either rightor left-handed operation of the machine.

According to this invention, a magnetoistarter whereinthe driven-1nember is pro vided with a notch or its equivalent to receive the pawl for holding it, which pawl is moved by yielding-control into the notch, and a part movable with the driving-member is provided, with a cam 0r itsequivalent to displace the pawl therefrom, is characterized by the co-opcrating parts of the notch and pawl or cam and pawl being such that when the driven-member is rotating at a predetermined speed or at a higher speed, thepawl will be thrown clear of the notch.

In the accompanying drawings which illustrate one method of carrying out this invention, y

Figure 1 shows the starter'in elevation; Figure 2 is a section through the starter on the line 2-2 of Figure 1;

s Figure 3 is a central section through the driven-member of the starter;

Figure 4 is a central section through the driving-member of the starter;

Figure 5 is a perspective view of the driving member, I

Figure 6 is a face view of that side of the driven-member which is engaged by the pawl, and I a I Figure 7 is a perspective view of a detail.

Like reference-characters indicate like parts throughout the drawings.

The starter comprises a disc-like drivenmember A which enters a dished driving member B. The drivenmember is recessed at A on that side which is towards the member B, and projecting into the recess from its periphery are two stops A The drivingmember B has two laterally projectingcams B which extend slightly beyond the member A, as shown in Figure 1. Within the driving-member are two studs B which lie against the stops A when the starter is running at speed. A flat spiral spring C connects one of the studs B to a, central boss A on the member A.

The magneto is indicated at D in Figure 1, and the member A is fast on its shaft D whereas the member B is carried by the driving-shaft E. In that face of the member A which is towards the magneto are two recesses A which conveniently are formed in the backs of the stops A A pawl F is mounted to swing about a pivot F whose axis is transverse to that of the axis of rotation of the starter, and the nose ofthe pawl is situated so that it cancenter the notches A. The pawl is weighted at F so that when it is in the position shown in full lines in Figure 1, itis yieldingly held against the face of the disc'A, but the weighted portion is so situated that when the pawl is swung back to the position indicated in chain-line, it is yieldingly held in that position.

For bringing the pawl back into the engaging-position, a swinging cradle G (F igures 1 and 7) is provided. This is a- U- shaped member mounted to swing on the pivot F of the pawl and arranged to extend round the back of the pawl and embrace it on either side. The cradle is connected by a spring G to a fixed part such as a portion of the magneto D, which spring tends always to keep the cradle back in the position shown in chain line in Figured A pull-cord G is, however, attached to it for the purpose of pulling it ,into the position shown in full lines.

It will be seen from this that, normally the cradle Gr lies free of the pawl, so that the pawl is quite unhampered in its movements, but when it is desired to bring the pawl F from its inoperative position, shown in chain line in Figure 1 to the operative po,

sition shown in full lines, the pull-cord G is operated in the direction of the arrow and thus the cradle G is brought forward and carries the pawl with it to the required position. The pull-cord is then releasedv and the cradle returns to the position shown in chain line, Figure 1 whereby the pawl is again left free.

A further means for holding the pawl in the disengaging position so that it may not be jolted therefrom by a movement from the vehicle upon which the magneto is used, consists in making the pawl of magnetizablc metal and so disposing it that in the disengaging position it comes into contact with one of the magnets of the magneto D, as indicated in Figure l.

It will be observed that the nose of the pawl is rounded, which is a feature of some importance as hereinafter described, and it is also of such width that it overhangs the periphery of the member A and thus lies in the path of the cams B of the member B.

The operation of this starter is as follows a When the driving-member is moved round slowly in the direction indicated by the arrow Figure 1, Figure 2, the driven-member is first held by the pawl F and the studs B thus move away from the stops A and increase the tension of the spring C. As the angular movement of the member B is continued, one of the cams B will be brought against the overhanging portion of the nose of the pawl F and thus will thrust the nose out from engagement with the notch in the member A. The member A then advances quickly under the action of the spring C so that the requisite spark is produced, and the parts A and B will run as one with the studs B bearing against the stops A If the pawl F is thrust right back by the I first disengagement, it remains in the position shown in chain-line, but if the speed should not be suflicient for this, it will be knocked back as the speed increases, either by its rounded end striking the edge of one ofthe notches A, or by striking one of the cams B before it has time to enter either of the notches. It will be appreciated that by widening the notches A, the speed at which the pawl will be refused admission can be regulated, and by causing the cams B to extend a little beyond the member A as shown, the pawl may even be prevented from com-, ing into contact with the edges of the notch at any speed beyond a given minimum. Thus if the movement of the members A and B when starting up is unduly slow, as for instance when the first spark does not fire the charge, the pawl will re-engage, but as soon as the engine starts up it is thrown back either by the cams B or by the thrust of the edges of the notches A, or by both.

\Vhenever-the starter is required to perform its function, it is only necessary to pull the pawl into position by the cord G which can have a convenient operating-member at the other end within reach of the driver.

if the spring G should break, the angular relation of the parts A and B will be disturbed. To meet this diiiiculty, a hole H is provided in the periphery of the member B, and a second hole H in the periphery of the member A. \Vhen these holes are in register, the parts are in the proper angular position for driving, and thus a split-pin can be pushed in to the holes H H to keep the parts in position, or they could be threaded to receive a screw.

It will be seen that all the parts of this starter are readily machined, which makes it inexpensive to manufacture, and moreover, they are so designed that the starter can be arranged to operate either left-handedly or right-handedly according to the design of the'engine with which it is to be used. As shown, it operates right-handedly, as viewed from the right in Figure 1, but to enable it to be driven left-handedly it is only necesary to reverse the spring C and put the pawl F on the other side of the shaft D A second hole could be provided in the periphery of the member A to register with the hole H when the parts were in the reversed position.

\Vhat I claim as my invention and desire to secure by Letters Patent is 1. In a magneto-starter the combination of a driving ,member', a driven-member formed with a slot whereof the opposed walls are disposed substantially symmetrical with respect to a plane normal to the direction of movement and passing through the centre of the slot, a spring connecting the driving-member to the driven-member,

a pawl pivotedto afixed part and yieldingly controlled to enter the said slot in the driven-member to lock it provisionally against movement with the driving-member and a cam movable with the driving member to displace the pawl from the slot after a given angular displacement of'the drivingmember has taken place, thelength of the slot between the opposed walls in the direction of rotation being selected to pre: determine the speed at which the pawl will be unable, by reason of its inertia, to enter the slot sufiiciently to engage therewith, and the nose of the pawl and the edges of the slot being rounded so that the pawl will engage the edge of the slot and readily free itself therefrom when it fails to enter sufficiently for engagement, substantially as described.

2. In a magneto-starter the combination with a driving-member, a driven-member, a spring connecting the driving-member to the driven-member, a pawl pivoted to a fixed part and yieldingly controlled to enter a slot in the driven-member to lock it provisionally against movement with the driving-member, and a cam movable with the driving member to displace the pawl from the slot after a given angular displacement of the driving-member has taken place, the pawl and its cooperating parts being so arranged that When the driven-member is rotating at a speed in excess of a predetermined minimum speed the pawl will be thrown clear of the slot in the driven-member, the pawl further being so disposed that when it is thrown out of th slot to the limit of its movement away from the same it lies against a part of the'magneto such that the pawl, being of suitable material, is magnetically held thereto substantially as described.

In testimony whereof I affix my signature.

JOHN FIFIELD ADYE. 

